1. Field of the Invention
The present invention relates to monitoring a system and a method for radio frequency (RF) processing units of a plurality of base stations in a wireless communication network, and, in particular, to a system and a method for remote monitoring spectrums of RF signals of the specific points at RF signal processing units, and controlling radio-frequency processing units of base stations in such networks after comparing the monitored spectrums with standard ones.
2. Brief Description of the Prior Art
The radio frequency(RF) processing unit including RF receiving and transmitting portion is one of the important units of a base station in a wireless communication network. The RF receiving portion comprises a receiving antenna; a low noise amplifier(LNA), which filters and amplifies the RF signal received through a receiving antenna; and a down converter which converts down the received RF signal(100 MHz.about.10 GHz) to an intermediate frequency(IF) signal(1 MHz.about.100 MHz). The RF transmitting portion comprises an up converter, which converts up an IF signal to an RF signal; a linear power amplifier(LPA), which amplifies the converted RF signal; and a transmitting antenna. The RF receiving/transmitting portion of base station is composed of analog circuits, so the functional characteristics of the RF signal processing unit gradually deteriorates unlike other units of the base station composed of digital circuits. Because of this gradual deterioration, it is difficult to detect faults or determine the time when an RF signal processing unit is to be replaced.
Technicians have conventionally visited each base station in order to check the functional status of the RF signal processing units by measuring their frequency characteristics with a spectrum analyzer to fix or replace the unit when its spectrum shape has changed from the normal spectrum shape. With such a human monitoring system, it is inconsistent and unreliable to decide about faults, repair time, or the replacement time for the RF signal processing unit; moreover, such a decision depends on the skill of the technician. As demand for high-quality service in wireless communication system demands more base stations, human monitoring system becomes less efficient and economical. Therefore, it becomes necessary to develop a new and effective monitoring systems and methods.